Rotary impact hammer for pulverizers



Dec. 22, 1953 Filed July 17, 1951 c. E. SENNHOLTZ 2,663,505

ROTARY IMPACT HAMMER FOR PULVERIZERS 2 Sheets-Sheet 1 INVENTOR. CharlesE. Sennholi} BY o/Lawn,

Dec. 22, 1953 c. E. SENNHOLTZ 2,663,505

ROTARY IMPACT HAMMER FOR PULVERIZERS Filed July 17, 1951 2 Sheets-Sheet2 INVENTOR.

Charles E. fiennhojy (3149)., 9413 M4 vwaif Patented Dec. 22, 1953UNITED [STAT ROTARY IMPACT HAMMER FOR PULVERIZERS Charles E. Sennholtz,Chicago, Ill. Application July 17, 1951, Serial No. 237,226

7 Claims. (Cl. 241-197) The present invention relates to rotary impactcrushers or pulverizers and more particularly to improvements in therevolving hammers ordinarily associated therewith.

In general, it is an object of the present invention to provide animproved hammer having a replaceable tip which may readily and easily beinstalled and removed and which is not susceptible to accidentaldisengagement, even under the most severe operating conditions.

A further object of the invention is to provide a pulverizing hammer anda replaceable tip therefor having novel engaging surfaces which are sodesigned that impact and centrifugal forces acting on the tip, in thecourse of use of the hammer, tend to increase the holding engagement ofthe tip without increasing the difficulty of removing the latter.

Another object is to provide a hammer having a replaceable tip in whichthe tip is securely retained on the hammer in a novel manner so that thetip and the engaging surfaces are susceptible to large tolerances insize permitting economical manufacture of the tip with a minimum ofmachining operations.

A still further object of the invention is to provide a hammer of thischaracter including a hammer proper and a replaceable tip, together witha wedge member by means of which the tip is securely locked in positionon the hammer proper against dislodgment. A similar and related objectis to provide a construction of this character in which the wedge memberis maintained in a locking relationship by means of a through-boltassembly, which latter assembly, when the hammer is in use, is 'solocated and positioned with respect to the other parts of the assemblythat no torsional shearing or compressional forces are transmitted tothe throughbolt assembly upon impact ofthe tip with the materialundergoing pulverizing.

It is another object of the invention to provide an improved pulverizinghammer which is in-' herently strong, rugged and durable so as towithstand shock and impact forces, and which has heavy duty workingsurfaces giving long and useful life against abrasive forces.

Finally, it is an object of the invention to provide a pulverizinghammer and a tip therefor which may be manufactured with fairly widetolerances in the fit of the various parts without endangering thelocking characteristics of the various parts when they are assembledupon the other.

other objects and advantages of the invention,

2 not at this time enumerated, will become apparent as the nature of theinvention is better understood.

In the accompanying two sheets of drawings forming a part of thisspecification:

Fig. 3 is a perspective view of the replaceabletip.

Fig. 4 is a perspective view of a wedge member employed in connectionwith the present invention.

Fig. 5 is a side elevational view of the hammer proper with the tipremoved.

Fig. 6 is a side elevational view of able tip, and

the replace- Fig. '7 is a side elevational view of the wedge member.

While the invention is susceptible of various modifications andalternative constructions, there is shown in the drawings and willherein be described in detail the preferred embodiment, but it is to beunderstod that it isnot thereby intended to limit the invention to theform dis- 1 closed, but it is intended to cover all modifications andalternative constructions falling within the spirit and scope of theinvention as expressed in the appended. claims.

In all of the above described views, similar characters of referencehave been employed to designate similar parts throughout. Referring moreparticularly to the drawings, an impact hammer l0 embodying the presentinvention is adapted for use with various types and kinds of crushers,pulverizers, mills, or the like. The hammer construction may be readilyunderstood without reference to the details of the pulverizer as awhole. It will suffice to say, how-. ever, that a plurality of suchhammers are pivoted at the periphery of a rotating disk and aremaintained in a radially extending direction due to the action ofcentrifugal force. The hammers are swung successively into contact witha mass of rock, coal or similar frangible material which is broken upinto a loose mass by the various impacts.

As disclosed in Figs. 1 and 2, the hammer; 10 comprises a hammer arm orshank I 2 and a hammer tip l4 (see also Fig. 3) removably secured to itsouter regions. The hammer arm-is pivoted in pendulous fashion at itsupper end on a suitable supporting shaft (not shown) adapted to extendthrough an opening l6 provided at the base of the hammer arm I2. Thehammer arm I2 is generally rectangular in cross section and is providedwith a leading face or wall l8 and side walls 28 and 22 extendingrearwardly therefrom.

Referring now to Fig. 2, the hammer arm I2 is provided with a relativelylarge substantially V-shaped notch 23 in the leading face 18 thereofwhich extends rearwardly of the hammer arm to a region approximatelyhalf-way between the leading face i8 and the trailing face or wall 24 ofthe hammer arm. The notch 23 is provided with a comparatively wide, flatbottom 26 having a relatively narrow, offset, inclined portion 23. Theinclined portion 28 of the bottom 26 of the notch 23 merges with a sidewall 36 and the flat bottom 26 merges with an opposed side wall 32, thetwo side walls 38 and 32 diverging forwardly and outwardly. A transversetongue 34 projects upwardly from the forward edge of the surface or wall36 and is of slightly less width than the widths of the hammer arm I2.The forward region of the wall or surface 32 is provided with a taperedrecess cr notch 56 therein which has its wide end at the juncturebetween the surfaces l8 and 32 and which has its narrow end at a medialregion of the surface 32. As will be described presently, the tongue 34is designed for cooperation with a recess provided in the hammer tip l4while the notch or recess 36 is designed for cooperation with aprojection provided on a Wedge member 38 associated with the hammerassembly and by means of which the hammer tip i4 is removably secured inposition on the hammer arm [2.

The hammer tip I4 is best illustrated in Fig. 3 and is generally ofL-shaped design. The hammer tip is provided with a body portion 40providing a leading impact surface 42 and a generally rounded endsurface 44 which, when the tip is in position on the hammer arm l2,constitutes an extension of the generally rounded outer end 46 of thehammer arm. The hammer tip I4 is also provided with a laterallyextending portion 48, the outer surface or end 59 of which is adapted tolie flush with and bear against the bottom surface 26 of the notch 23provided on the hammer arm l2 when the two parts are in assembledposition. The laterally extending portion 48 provides a surface 52which, when the tip is assembled on the arm, opposes the surface 32provided on the hammer arm. The surface 52 of the hammer tip !4 isprovided with a tapered recess 54 which is complementary in shape to andis designed for cooperation with a second projection provided on thewedge member 38. The lateral portion 48 of the hammer tip 14 is alsoprovided with an inner surface 56 adapted to lie flush with and bearagainst the inner side wall 36 of the notch 23 when the parts areassembled. An elongated recess or groove 63 is formed in the tip I4 atthe juncture between the surface 56 and the inner surface 6! of the bodyportion 40 of the tip l4 and is adapted to re- 7 I ceive the tongue 34therein when the parts are iassembled. The tongue 34 and groove 36 areof substantially the same proportions and are complementary in shape toeach other so that ay be received within the other with hammer arm l2with the tongue 34 fitting into the recess 66, the surface 52 of the tipand the surface or side wall 32 of the notch 23 in the hammer arm i2provides therebetween a substantially V-shaped space in which there isadapted to be received the wedge member 33 for locking the two partstogether.

The wedge member 38 is illustrated in detail in Fig. 4 and includes atapered body portion of substantially the same width as the width of thehammer arm [2 and having one inclined face 62 adapted to fit against theface 32 and another inclined face 64 adapted to fit against the face 52when the wedge member 38 is in position in the assembled structure. Thesmall end or bottom surface 66 of the wedge member 33 is adapted to fitagainst the bottom wall 23 of the notch 23 when the parts are assembled.The face 62 of the wedge member 33 is provided with a raised tapered lug68 complemental in shape to the tapered recess 36 provided in the wall32 of the notch 23 and a similar raised wedge-shaped projection 70 isformed on the surface 64 of the wedge member 38, this latter projectionit being substantially complemental in shape to the recess 54 providedin the surface 32 of the hammer tip I4. Thus, when the parts are intheir assembled relationship with the wedge member 38 fitting into thespace existing between the opposed wall surfaces 32 and 52, theprojection 66 fits more or less snugly within the recess 36 and theprojection 10 fits more or less snugly within the recess 54.

The small end of the tapered wedge member 38 is provided with a T-shapedslot 72 therein (Figs. 4 and 7) adapted to receive therein the head 14of a through bolt 16. The threaded end of the bolt 16 projects into arecess 18 provided in the trailing face 24 of the hammer arm 10, and anut 80, which may be of hexagonal design, is received on the threadedend of the bolt 16 and is wholly contained within the confines of therecess 18 to hold the Wedge member 38 firmly in position in the hammerassembly. A bore 82, which communicates with the recess 18 and bottom ofthe notch 23, extends through the body portion of the hammer arm 12 toaccommodate the through bolt 16.

Referring now to Fig. 1, it will be seen that when the various partsincluding the hammer arm I2, hammer tip l4 and wedge member 38 are inassembled relationship, the combined width of the hammer arm l2 and thetip I4 in the direction of swinging movement of the hammer arm isslightly greater than the width of the shank portion of the arm and thusthe leading impact surface 42 of the tip l4 projects forwardly a slightdistance beyond the leading wall I8 of the hammer arm l2 to provide animpact surface somewhat in advance of the plane of the leading surfaceof the hammer arm 2.

The leading face 84 of the hammer arm l2 below the notch 23 issubstantially flat and is inclined downwardly and rearwardly withrespect to the vertical when the hammer arm is in the vertical positionin which it is shown in Fig. 1. Similarly, the opposing face 6| of thehammer tip 46 is also inclined in this manner so as to lie against theface 84 when the parts are assembled. The inner surface 86 of the tongue34 (Figs. 1 and 5) and the mating surface 88 of the groove 68 are alsoinclined in a plane substantially parallel to the plane of the surfaces6| and 64.

.b n th when entrifugal forces are ti hm tip L4. ther s'a endency forthe tip to be drawn inwardly toward the central plane of the hammer arm12, thus enhancing the wedging action between these two parts. Even inthe absence of the Wedge member 38 and through bolt assembly 16, thetendency would be for the two parts [2 and M of the hammer assembly toremain locked together during rotation of the pulverizer assembly.

The hammer arm l2, hammer tip l4 and wedge member 38 are respectivelyshown in Figs. 5, 6 and 7 and these latter figures are arranged on asingle sheet of drawing so that their parts occupy substantially thesame positions of orientation with respect to the vertical plane thatthey will occupy when the parts are assembled together. Thus, whenassembling the parts, it is merely necessary to elevate the hammer tip I4 a sufficient distance so that the surface 50 thereof clears the tongue34, after which the parts may be moved horizontally toward each otheruntil the tongue 34 registers vertically with the groove 60. The hammertip [4 may then be lowered into position so that the tongue 34 entersthe groove 66. The wedge member 33 may then be inserted in the taperedspace which has thus been created by the positioning of the tip upon thehammer arm. As the surfaces 62 and 32 and the surfaces 64 and 30,respectively, of the wedge member 38 and hammer arm I2 move toward eachother, the tapered projections 68 and 10 enter the notches or recesses3t and 54, respectively, of the hammer arm l2 and tip I4. Thethrough-bolt 16, which has been previously placed in position with thehead 74 thereof disposed within the T-shaped slot 12, is guided throughthe bore 82 and thereafter the nut 80 may be applied to the threadedportion thereof and tightened to firmly clamp the parts in position. Bya reversal of this process the various parts may be disassembled.

It will be apparent that since all the essential mating surfaces betweenthe various parts are tapered, there are no surfaces which need to bemachined to a fine tolerance in order to insure smooth, slidingengagement. As a matter of fact, the hammer tip l4 may be in the form ofa simple casting and may be constructed in th form illustrated withoutany machining processes whatsoever. Since it is unnecessary that the tipbe precisely fitted to the hammer arm to avoid looseness of play, itwill be apparent that considerable dimensional variation is permissibleand the tip may be turned out at a relatively low cost. This latterpoint is of particular advantage when it is remembered that the tip mustbe replaced at intervals due to the abrasion of the pulverizing materialupon which it operates. If the tips are formed of cast steel it will beseen that the tapered surfaces thereof will provide proper draft foreasy removal of the pattern from the mold, for example, if the partingline of the mold is drawn diagonally from the upper rear corner of theflange portion 52 to the lower leading corner of the impact face 42.

Several of the advantages of the above described construction areapparent in Figs. 1, 5 and 6. It will be seen that the lower region ofthe hammer arm 12 provides a relatively strong columnar support for thehammer tip I4 and that the tapered body portion 49 of the tip I 4provides a large mass of metal for taking the brunt of the Wear on thetip. Inasmuch as the leading face 52 of the tip [4 projects beyond theleading face l8 of the hammer arm [2, a, certain amount of metal isprovided for excess wear prior to the time th'at'the leading face l8 ofthe hammer arm is endangered. However, the wear on the leading face 42of the tip I4 is not uniform and those portions of the tip which arefurthest removed from the axial center of rotation of the hammer arm arethe portions which are subject to the most wear. Thus the fact that thebody portion 40 of the tip I4 is thicker adjacent the outer regionsthereof than it is at regions which are inwardly removed therefromresults in an equitable distribution of the metal so that more metal ispresented for wear at the region where wear is to be expected. Thedotted lines in Fig. 1 indicated at w indicate the possible wear surfacethat may ultimately result immediately prior to the time when it isnecessary to replace the tip M. It will be seen, therefore, that theleading face l8 of the hammer arm [2 is thus protected against damage byvirtue of the excess metal afforded at the outer regions of the tip bythe tapered body portion thereof.

I claim as my invention; 7 v

1. An impact hammer for rotary pulverizers comprising, in combination, ahammer arm presenting a leading and a trailing face, there being a notchformed in said arm adjacent the outer free end thereof extendinginwardly from said leading face, a removable and generally L-shapedhammer tip of one-piece construction including a body portion presentingan impact face and a trailing'face, and a flange portion extendinglaterally from said body portion and presenting innor and outer faces,said-flange portion being received in said notch with its inner face incontact with one wall of the notch, the trailing face of said bodyportion being in contact with the leading face of said hammer armoutwardly of said notch, a wedge member disposed in said notch andbearing against the other wall of the notch and against the outer faceof said flange portion to maintain the flange portion in position in thenotch, and a locking bolt assembly secured at one end to the wedgemember and pass ing through said hammer arm for locking said wedgemember in position.

2. An impact hammer for rotary pulverizers comprising, in combination, ahammer arm presenting leading and trailing faces, there being a notchformed in said arm adjacent the outer free end thereof extendinginwardly from said leading face and having inwardly tapered walls, ahammer tip of one-piece construction including a body portion presentingan impact face in advance of the leading face of said hammer arm and atrailing face in contact with the leading face of said hammer armoutwardly of said notch, said tip having a laterally projecting portionextending into said notch, a wedge member disposed in said notch andhaving one face thereof bearing against a wall of the notch and theother face thereof bearing against said hammer tip for retaining thelatter in position on the hammer arm, and means extending through saidhammer arm from the trailing face thereof and projecting into said wedgemember for locking the latter in position within said notch.

3. An impact hammer for rotary pulverizers comprising, in combination, ahammer arm presenting a leading and a trailing face, there being a notchformed in said arm adjacent the outer free end thereof extendinginwardly from said leading face, said notch having opposed inwardlytapering walls, a removable, generally L-shaped hammer tip of one-piececonstruction including a body portion presenting an impact face and atrailing face, and a flange portion extending :laterally from said body:portion and presenting innor and outer ,fa'ces, .sa-id :flange portionbeing received in said notch w-ith its inner face in contact with'onewall-of the latter, the trailing face of said body portion being incontact with the leading face of the hammer arm outwardly of said notch,there being a @groove formed in the outer face of said flange portion,there being a groove formed inone wall of said notch,a tapered wedgereceived within-saidznotch and having projections formed thereon fittinginto said grooves.

said wedge member serving to retain said hammer tip in position on said-hammer arm, and means extending through said hammer arm and engagingsaid wedge .member for locking the latter in position within said.notc-h.

'4. In combination, a hammer arm for rotary pulverizers having a notchformed in the outer regions thereof extending inwardly from its leadingface, a removable tip tor said arm including a body portion overlyingthe leading face of said arm outlardly of the notch and in contacttherewith, said tip having a laterally extending portion'thereofprojecting into said notch and bearing against one wall thereof,interlocking upright abutments on said wall of said notch and on saidlaterally extending portion for preventing forward movement of thelatter outwardly of the notch, a rearwardly tapered wedge memberdisposed in said notch and bearing against the other wall of the notchand against said laterally extending portion for locking said laterallyextending portion inposition within said notch, and

v fastening means for holding said wedge against dislodgment from saidnotch.

5. In combination, a hammer arm for rotary pulverizers having a leadingface and a trailing face, a forwardly extending jaw adjacent the outerend of said arm terminating rearwardly of said leading face, said armand jaw being of the same uniform width, an inwardly extending tongueformed on the forward end of said jaw, a removable hammer tip includinga body portion abutting against the forward end of said jaw, there beinga groove in said tip into which said tongue extends, a Wedge memberfitting between a face of said body portion and a face of said hammertip for maintaining said hammer tip in position on the hammer arm, and abolt extending through said hammer arm and secured in said wedge memberfor locking the latter in position against the hammer tip and hammerarm.

8i 6. In combination, a hammer arm for rotary pulverizers having a notchformed in the outer regions thereof extending inwardly from its leadingface, a removable tip for said arm including a body portion overlyingthe leading face of said arm outwardly of said notch, said tip having arearwardly extending portion projecting into said notch and in contactwith one wall thereof, a rearwardly tapered wedge member disposed insaid notch, a first tongue and groove connection between said Wedge andthe other wall of said notch, a second tongue and groove connectionbetween said wedge and said rearwardly extending portion of said tip,said first and second tongue groove connections preventing relativesidewise displacement of said wedge, and fastening means for holdingsaid wedge against displacement forwardly out of said notch.

7-. In combination, a hammer arm for rotary pulverizers having a leadingface and a trailing face, a notch formed in the outer regions of saidarm extending rearwardly from said leading face, a removable hammer tipincluding a body portion abutting the leading face of said arm outwardlyof said notch and a rearwardly ex tending flange portion projecting intosaid notch and engaging one wall thereof, said wall and said flangehaving a transversely extending tongue and groove connectionthereb'etvve'en, a rearward-.

1y tapered wedge positioned in said notch between said flange portionand the other wall of said notch, a first forwardly and rearwardlyextending tongue and groove connection between said wedge and the otherwall of said notch, a second forwardly and rearwardly extending tongueand groove connection between said wedge and said flange, said first andsecond connections preventing relative sidewi'se movement of said wedge,and fastening means extending through said hammer arm for restrainingsaid wedge against displacement forwardly out of said notch.

CHARLES E. SENNHOLTZ.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,186,071 Bledsoe June 6, 1916 1,491,416 Plaisted Apr. 22,1924 1,491,417 Plaisted l Apr. 22, 1924 1,630,021 Lucas May 24, 19272,531,597 Anderson Nov. 28, 1950. 2,534,301 Sennholtz 1 Dec. 19, 1950ars". o

